[2/2] Minor refactoring of tree-vect-patterns.c

Hello,

as a second step in refactoring this patch introduces a routine
vect_find_single_use to determine whether a defining statement
has one single use within the current vectorization domain.

The helper is then called wherever that check is currently
open-coded.  There should be no change in behaviour.

Tested on i386-linux-gnu and arm-linux-gnueabi with no regressions.

OK for mainline?

Bye,
Ulrich


ChangeLog:

	* tree-vect-patterns.c (vect_find_single_use): New function.
	(vect_recog_widen_mult_pattern): Use it instead of open-coding loop.
	(vect_recog_over_widening_pattern): Likewise.
	(vect_recog_widen_shift_pattern): Likewise.

On Mon, Apr 30, 2012 at 6:19 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> Hello,
>
> as a second step in refactoring this patch introduces a routine
> vect_find_single_use to determine whether a defining statement
> has one single use within the current vectorization domain.
>
> The helper is then called wherever that check is currently
> open-coded.  There should be no change in behaviour.
>
> Tested on i386-linux-gnu and arm-linux-gnueabi with no regressions.
>
> OK for mainline?

You can use single_imm_use to avoid the loop and simplify the factored
routine.

Ok with that change.

Thanks,
Richard.

> Bye,
> Ulrich
>
>
> ChangeLog:
>
>        * tree-vect-patterns.c (vect_find_single_use): New function.
>        (vect_recog_widen_mult_pattern): Use it instead of open-coding loop.
>        (vect_recog_over_widening_pattern): Likewise.
>        (vect_recog_widen_shift_pattern): Likewise.
>
>
> Index: gcc-head/gcc/tree-vect-patterns.c
> ===================================================================
> --- gcc-head.orig/gcc/tree-vect-patterns.c      2012-04-26 19:46:12.000000000 +0200
> +++ gcc-head/gcc/tree-vect-patterns.c   2012-04-26 19:46:53.000000000 +0200
> @@ -119,6 +119,33 @@ vect_same_loop_or_bb_p (gimple stmt1, gi
>   return true;
>  }
>
> +/* If the LHS of DEF_STMT has a single use, and that statement is
> +   in the same loop or basic block, return it.  */
> +
> +static gimple
> +vect_find_single_use (gimple def_stmt)
> +{
> +  tree lhs = gimple_assign_lhs (def_stmt);
> +  imm_use_iterator imm_iter;
> +  use_operand_p use_p;
> +  gimple use_stmt = NULL;
> +
> +  FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
> +    {
> +      if (is_gimple_debug (USE_STMT (use_p)))
> +       continue;
> +
> +      if (use_stmt)
> +       return NULL;
> +      use_stmt = USE_STMT (use_p);
> +
> +      if (!vect_same_loop_or_bb_p (def_stmt, use_stmt))
> +       return NULL;
> +    }
> +
> +  return use_stmt;
> +}
> +
>  /* Check whether NAME, an ssa-name used in USE_STMT,
>    is a result of a type promotion or demotion, such that:
>      DEF_STMT: NAME = NOP (name0)
> @@ -636,31 +663,18 @@ vect_recog_widen_mult_pattern (VEC (gimp
>      Use unsigned TYPE as the type for WIDEN_MULT_EXPR.  */
>   if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (half_type0))
>     {
> -      tree lhs = gimple_assign_lhs (last_stmt), use_lhs;
> -      imm_use_iterator imm_iter;
> -      use_operand_p use_p;
> -      int nuses = 0;
> -      gimple use_stmt = NULL;
> +      gimple use_stmt;
> +      tree use_lhs;
>       tree use_type;
>
>       if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (half_type1))
>         return NULL;
>
> -      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
> -        {
> -         if (is_gimple_debug (USE_STMT (use_p)))
> -           continue;
> -          use_stmt = USE_STMT (use_p);
> -          nuses++;
> -        }
> -
> -      if (nuses != 1 || !is_gimple_assign (use_stmt)
> -          || gimple_assign_rhs_code (use_stmt) != NOP_EXPR)
> +      use_stmt = vect_find_single_use (last_stmt);
> +      if (!use_stmt || !is_gimple_assign (use_stmt)
> +         || gimple_assign_rhs_code (use_stmt) != NOP_EXPR)
>         return NULL;
>
> -      if (!vect_same_loop_or_bb_p (last_stmt, use_stmt))
> -       return NULL;
> -
>       use_lhs = gimple_assign_lhs (use_stmt);
>       use_type = TREE_TYPE (use_lhs);
>       if (!INTEGRAL_TYPE_P (use_type)
> @@ -1165,10 +1179,7 @@ vect_recog_over_widening_pattern (VEC (g
>  {
>   gimple stmt = VEC_pop (gimple, *stmts);
>   gimple pattern_stmt = NULL, new_def_stmt, prev_stmt = NULL, use_stmt = NULL;
> -  tree op0, op1, vectype = NULL_TREE, lhs, use_lhs, use_type;
> -  imm_use_iterator imm_iter;
> -  use_operand_p use_p;
> -  int nuses = 0;
> +  tree op0, op1, vectype = NULL_TREE, use_lhs, use_type;
>   tree var = NULL_TREE, new_type = NULL_TREE, tmp, new_oprnd;
>   bool first;
>   tree type = NULL;
> @@ -1192,18 +1203,8 @@ vect_recog_over_widening_pattern (VEC (g
>         }
>
>       /* STMT can be performed on a smaller type.  Check its uses.  */
> -      lhs = gimple_assign_lhs (stmt);
> -      nuses = 0;
> -      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
> -        {
> -          if (is_gimple_debug (USE_STMT (use_p)))
> -            continue;
> -          use_stmt = USE_STMT (use_p);
> -          nuses++;
> -        }
> -
> -      if (nuses != 1 || !is_gimple_assign (use_stmt)
> -         || !vect_same_loop_or_bb_p (stmt, use_stmt))
> +      use_stmt = vect_find_single_use (stmt);
> +      if (!use_stmt || !is_gimple_assign (use_stmt))
>         return NULL;
>
>       /* Create pattern statement for STMT.  */
> @@ -1454,12 +1455,6 @@ vect_recog_widen_shift_pattern (VEC (gim
>      Use unsigned TYPE as the type for WIDEN_LSHIFT_EXPR.  */
>   if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (half_type0))
>     {
> -      tree lhs = gimple_assign_lhs (last_stmt), use_lhs;
> -      imm_use_iterator imm_iter;
> -      use_operand_p use_p;
> -      int nuses = 0;
> -      tree use_type;
> -
>       if (over_widen)
>         {
>           /* In case of over-widening pattern, S4 should be ORIG_STMT itself.
> @@ -1472,21 +1467,14 @@ vect_recog_widen_shift_pattern (VEC (gim
>         }
>       else
>         {
> -          FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
> -            {
> -             if (is_gimple_debug (USE_STMT (use_p)))
> -               continue;
> -             use_stmt = USE_STMT (use_p);
> -             nuses++;
> -            }
> +         tree use_type;
> +         tree use_lhs;
>
> -          if (nuses != 1 || !is_gimple_assign (use_stmt)
> +         use_stmt = vect_find_single_use (last_stmt);
> +         if (!use_stmt || !is_gimple_assign (use_stmt)
>              || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (use_stmt)))
>            return NULL;
>
> -         if (!vect_same_loop_or_bb_p (last_stmt, use_stmt))
> -           return NULL;
> -
>           use_lhs = gimple_assign_lhs (use_stmt);
>           use_type = TREE_TYPE (use_lhs);
>
> --
>  Dr. Ulrich Weigand
>  GNU Toolchain for Linux on System z and Cell BE
>  Ulrich.Weigand@de.ibm.com
>